High pressure liquid chromatography (HPLC) systems sometimes require that a sample be diluted before it is injected into the mobile phase flowing to a chromatography column. Various reasons exist for diluting the sample prior to injection. For example, a system may not be capable of injecting a sufficiently small quantity of sample (e.g., picoliters) to avoid a mass overload condition for the chromatography column. Alternatively, the native solvent containing the sample may be inappropriate for the stationary phase due to a physical property (e.g., pH level) of the solvent. In another example, the sample may be dissolved in a strong solvent that interacts with the stationary phase, leading to ambiguous results in the chromatogram.
Dilutions can be performed manually by a skilled technician; however, it is not always practical to keep a technician available to perform dilutions. In many instances, the technician and equipment for performing the dilution are located an inconvenient distance from the HPLC system. Significant delay can occur if the sample is transferred to a remote location for dilution, potentially resulting in manufacturing or processing downtime. Moreover, the additional inconvenience of tracking the transported sample is often necessary.
The present invention addresses the problems set forth above and provides additional advantages.